High range positive voltage level shifter using low voltage devices

Abstract

A voltage level shifter is provided. The voltage level shifter includes an input stage and at least one level shifting stage. The input stage receives an input voltage and a complementary input voltage and receives a first supply voltage and a ground voltage. The input stage outputs one of the first supply voltage and the ground voltage over a first output voltage node and a first complementary output voltage node based on the input voltage and the complementary input voltage. A level shifting stage is coupled to the input stage. The level shifting stage receives the first supply voltage and a second supply voltage and outputs one of the ground voltage, the first supply voltage and the second supply voltage over second and third output voltage nodes and second and third complementary output voltage nodes based on voltages of the first output voltage node and the first complementary output voltage node.

The invention claimed is: 
     
       1. A voltage level shifter, comprising:
 an input stage having an input voltage node, a complementary input voltage node, a first output voltage node and a first complementary output voltage node; and 
 a first level shifting stage including:
 a first output transistor having first and second conduction terminals coupled to the first output voltage node and a second output voltage node, respectively, and a gate coupled to a first supply voltage node; 
 a first complementary output transistor having first and second conduction terminals coupled to a second complementary output voltage node and a second supply voltage node, respectively; and 
 first and second transistors that are cross-coupled, the first transistor having a first conduction terminal coupled to a gate of the first complementary output transistor, a second conduction terminal coupled to the first supply voltage node, and a gate coupled to the second output voltage node, the second transistor having a first conduction terminal coupled to the gate of the first complementary output transistor, a second conduction terminal coupled to the second output voltage node, and a gate coupled to the first supply voltage node. 
 
 
     
     
       2. The voltage level shifter of  claim 1 , wherein the input stage includes:
 an input transistor having first and second conduction terminals coupled to the first complementary output voltage node and a ground node, respectively, and a gate coupled to the input voltage node; 
 a complementary input transistor having a first and a second conduction terminals coupled to the first output voltage node and the ground node, respectively, and a gate coupled to the complementary input voltage node; and 
 a first input stage cross-coupled transistor and a second input stage cross-coupled transistor. 
 
     
     
       3. The voltage level shifter of  claim 2 , wherein the first input stage cross-coupled transistor has first and second conduction terminals coupled to the first supply voltage node and the first complementary output voltage node, respectively, and a gate coupled to the first output voltage node, and the second input stage cross-coupled transistor has first and second conduction terminals coupled to the first supply voltage node and the first output voltage node, respectively, and a gate coupled to the first complementary output voltage node. 
     
     
       4. The voltage level shifter of  claim 1 , wherein the first level shifting stage includes:
 a second output transistor having a first conduction terminal coupled to the second output voltage node and a second conduction terminal coupled to a third output voltage node, respectively, and a gate coupled to the first supply voltage node; and 
 a third output transistor having a first conduction terminal coupled to the third output voltage node and a second conduction terminals coupled to the second supply voltage node, and a gate. 
 
     
     
       5. The voltage level shifter of  claim 1 , wherein the first level shifting stage includes:
 a second complementary output transistor having a first conduction terminal coupled to the first complementary output voltage node, a second conduction terminal coupled to a third complementary output voltage node, and a gate coupled to the first supply voltage node; and 
 a third complementary output transistor having first and second conduction terminals coupled to the second and third complementary output voltage nodes, respectively, and a gate coupled to the first supply voltage node. 
 
     
     
       6. The voltage level shifter of  claim 5 , wherein the first level shifting stage includes:
 a third and a fourth transistors that are cross-coupled, the third transistor having a first conduction terminal coupled to the gate of the third output transistor, a second conduction terminal coupled to the first supply voltage node, and a gate coupled to the third complementary output voltage node, the second transistor having a first conduction terminal coupled to the gate of the third output transistor, a second conduction terminal coupled to the third complementary output voltage node, and a gate coupled to the first supply voltage node. 
 
     
     
       7. The voltage level shifter of  claim 1 , wherein the first level shifting stage includes:
 a fifth transistor having a first conduction terminal coupled to the second complementary output voltage node, a second conduction terminal coupled to the first supply voltage node and a gate coupled to the gate of the first complementary output transistor; and 
 a sixth transistor having a first conduction terminal coupled to the third output voltage node, a second conduction terminal coupled to the first supply voltage node and a gate coupled to the gate of the third output transistor. 
 
     
     
       8. The voltage level shifter of  claim 1 , comprising:
 a second level shifting stage coupled to the third output voltage node, the second complementary output voltage node, fourth and fifth output voltage nodes and fourth and fifth complementary output voltage nodes, the second level shifting stage being configured to: 
 receive a second supply voltage and a third supply voltage; and 
 output one of a first supply voltage, the second supply voltage and the third supply voltage over the fourth and fifth output voltage nodes and the fourth and fifth complementary output voltage nodes based on voltages of the third output voltage node and the second complementary output voltage node. 
 
     
     
       9. The voltage level shifter of  claim 8 , wherein the second level shifting stage has an identical structure as the first level shifting stage. 
     
     
       10. The voltage level shifter of  claim 1 , wherein the input stage is configured to:
 receive an input voltage over the input voltage node and a complementary input voltage over the complementary input voltage node; 
 receive a first supply voltage and a ground voltage; 
 output one of the first supply voltage and the ground voltage over the first output voltage node based on the input voltage and the complementary input voltage; and 
 output one of the first supply voltage and the ground voltage over the first complementary output voltage node based on the input voltage and the complementary input voltage. 
 
     
     
       11. The voltage level shifter of  claim 10 , wherein the input stage is configured to output the ground voltage over the first output voltage node and the first supply voltage over the first complementary output voltage node when the input voltage is the ground voltage and the complementary input voltage node is an on voltage, and the input stage is configured to output the first supply voltage over the first output voltage node and the ground voltage over the first complementary output voltage node when the input voltage is the on voltage and the complementary input voltage node is the ground voltage. 
     
     
       12. The voltage level shifter of  claim 10 , wherein the first level shifting stage is configured to output a ground voltage over the second output voltage node, and a second supply voltage over the second complementary output voltage node when the input voltage is the ground voltage and the complementary input voltage node is an on voltage, and the first level shifting stage is configured to output the second supply voltage over the second output voltage node, and the first supply voltage over the second complementary output voltage node when the input voltage is the on voltage and the complementary input voltage node is the ground voltage. 
     
     
       13. The voltage level shifter of  claim 8 , wherein the second level shifting stage is configured to output the first supply voltage over the fourth output voltage node, the second supply voltage over the fifth output voltage node, and the third supply voltage over both the fourth and fifth complementary output voltage nodes when an input voltage of the input voltage node is the ground voltage and an input voltage of the complementary input voltage node is an on voltage, and the second level shifting stage is configured to output the third supply voltage over both the fourth and fifth output voltage nodes, the first supply voltage over the fourth complementary output voltage node, and the second supply voltage over the fifth complementary output voltage node when the input voltage of the input voltage node is the on voltage and the input voltage of the complementary input voltage node is the ground voltage. 
     
     
       14. A method, comprising:
 receiving, by an input stage, an input voltage, a complementary input voltage, a ground voltage and a first supply voltage, the first supply voltage being received over a first supply voltage node; 
 outputting, based on the input voltage and the complementary input voltage, a first output voltage, over a first output voltage node, as one of the first supply voltage and the ground voltage and a first complementary output voltage, over a first complementary output voltage node, as another one of the first supply voltage and the ground voltage; 
 receiving, by a first level shifting stage, the first output voltage, the first complementary output voltage, the first supply voltage, and a second supply voltage the second supply voltage being received over a second supply voltage node; and 
 outputting, by the first level shifting stage based on the first output voltage and the first complementary output voltage, a second output voltage over a second output voltage node, a second complementary output voltage over a second complementary output voltage node, a third output voltage over a third output voltage node, and a third complementary output voltage over a third complementary output voltage node from one of the ground voltage, the first supply voltage and the second supply voltage, the first level shifting stage including:
 a first output transistor having first and second conduction terminals coupled to the first output voltage node and the second output voltage node, respectively, and a gate coupled to the first supply voltage node; 
 a first complementary output transistor having first and second conduction terminals coupled to the second complementary output voltage node and the second supply voltage node, respectively; and 
 first and second transistors that are cross-coupled, the first transistor having a first conduction terminal coupled to a gate of the first complementary output transistor, a second conduction terminal coupled to the first supply voltage node, and a gate coupled to the second output voltage node, the second transistor having a first conduction terminal coupled to the gate of the first complementary output transistor, a second conduction terminal coupled to the second output voltage node, and a gate coupled to the first supply voltage node. 
 
 
     
     
       15. The method of  claim 14 , wherein outputting the first output voltage as one of the first supply voltage and the ground voltage and the first complementary output voltage as another one of the first supply voltage and the ground voltage includes outputting the first output voltage as the ground voltage and the first complementary output voltage as the first supply voltage on a condition that the input voltage is the ground voltage and the complementary input voltage is the first supply voltage. 
     
     
       16. The method of  claim 15 , wherein outputting the first output voltage as one of the first supply voltage and the ground voltage and the first complementary output voltage as another one of the first supply voltage and the ground voltage includes outputting the first output voltage as the first supply voltage and the first complementary output voltage as the ground voltage on a condition that the input voltage is the first supply voltage and the complementary input voltage is the ground voltage. 
     
     
       17. The method of  claim 14 , wherein outputting the second output voltage, the second complementary output voltage, the third output voltage, and the third complementary output voltage includes outputting the second output voltage as the ground voltage, the third output voltage as the first supply voltage, the second complementary output voltage as the second supply voltage and the third complementary output voltage as the second supply voltage on a condition that the first output voltage is the ground voltage and the first complementary output voltage is the first supply voltage. 
     
     
       18. The method of  claim 14 , wherein outputting the second output voltage, the second complementary output voltage, the third output voltage, and the third complementary output voltage includes outputting the second output voltage as the second supply voltage, the third output voltage as the second supply voltage, the second complementary output voltage as the second supply voltage and the third complementary output voltage as the second supply voltage on a condition that the first output voltage is the first supply voltage and the first complementary output voltage is the ground voltage. 
     
     
       19. The method of  claim 14 , comprising:
 receiving, by a second level shifting stage, the third output voltage, the second complementary output voltage, and a third supply voltage; and 
 outputting, by the second level shifting stage based on the third output voltage and the second complementary output voltage, a fourth output voltage, a fourth complementary output voltage, a fifth output voltage, and a fifth complementary output voltage from one of the first supply voltage, the second supply voltage and the third supply voltage. 
 
     
     
       20. A voltage level shifter, comprising:
 an input stage coupled between a first supply voltage node and a ground terminal and having an input voltage node, a complementary input voltage node, a first output voltage node and a first complementary output voltage node, the input stage being configured to provide the first supply voltage at the first complementary output voltage node and the ground voltage at the first output voltage node in response to receiving an input voltage at the input voltage; and 
 a level shifting stage including:
 a first transistor having a conduction path coupled between the first output voltage node and a second output voltage node, and a control terminal coupled to the first voltage supply node; 
 a second transistor having a conduction path coupled between a second complementary output voltage node and a second supply voltage node; and 
 first and second cross-coupled transistors, the first cross-coupled transistor having a conduction path coupled between the control terminal of the second transistor and the first supply voltage node and a control terminal coupled to the second output voltage node, and the second cross-coupled transistor having a conduction path coupled between the control terminal of the second transistor and the second output voltage node and a control terminal coupled to the first supply voltage node. 
 
 
     
     
       21. The voltage level shifter of  claim 20 , wherein the level shifting stage includes:
 a third transistor having a conduction path coupled between the first complementary output voltage node and a second complementary output voltage node, and a control terminal coupled to the first voltage supply node; 
 a fourth transistor having a conduction path coupled between a third output voltage node and the second supply voltage node; and 
 third and fourth cross-coupled transistors, the third cross-coupled transistor having a conduction path coupled between the control terminal of the fourth transistor and the first supply voltage node and a control terminal coupled to the second complementary output voltage node, and the fourth cross-coupled transistor having a conduction path coupled between the control terminal of the fourth transistor and the second complementary output voltage node and a control terminal coupled to the first supply voltage node.